Method and apparatus for making tubes



Nov. 6, 1934. w. BARK ET AL METHOD AND APPARATUS FOR MAKING TUBES Filed June 2, 1932 imam??? W/LL/A M 5 45% a H550 /4 Mar e/WAN.

Patented Nov. 6, 1934 UNITED STATES PATENT OFFICE l TUBE William Bark, Gary, Ind., and Fred W. Waterman, Pittsburgh, Pa., assignors to National Tube Company, a corporation of New Jersey v Application June 2, 1932, Serial No. 615,016

9 Claims. (01. 80-11) This invention relates to a tube mill layout, one of the objects being to manufacture tubes in a more efficient manner with fewer stops. Other objects may be understood from the following. The accompa y g drawing shows a schematic plan of this new layout, Figure 1, and a detail end elevation of one of the units thereof, Figure 2. Having reference to the drawing, a rotary rolling mill 1 is shown arranged close to a reeling machine 2. A pierced billet is rolled into a tube by this rotary mill and then transferred to the reeling machine for truing and polishing.

If the rolled tubes outside diameter is either too large or too small it cannot possibly be properly reeled. This is because reeling machines cannot get a proper bite on tubes which are too large and also because tubes that are slight- 1y undersized will jam on the reeling machines mandrel 2, which is fixedly positioned between the reeling rolls. Consequently, it is necessary to operate the rotary rolling mill so as to produce tubes whose outside diameters do not vary beyond the extremely narrow range necessary for this reeling operation. The adherence to this necessarily strict tolerance is extremely diflicult as it is hard to operate a rotary mill with such accuracy. The present invention includes the use of a sinking-sizing machine 3 interposed between .the rotary rolling mm 1 and the reeling machine 2. This sinking-sizing machine consists of a single stand whose rolls are constructed to' form as perfect a circular pass as is mechanically possi-- ble. A conveying table 4 served with tubes from 3 the rolling. mill 1 by an incline 5 is provided.

This table carries the tubes through the sinkingsizing machine 3 and delivers them to a second incline 6 which serves the reeling machines ingoing trough.

The method of lows: V

The rotary mill 1 rolls a rough. pierced billet into a tube which is slightly larger than that demanded by the reeling machine 2. No effort is made to maintain the extremely strict tolerance heretofore required, care being taken only to be sure the tube is not rolled undersized. This 1 tube is then dropped down the incline 5 to the table 4 and is carriedthrough the sinking-sizing machine 3. This machine is constructed so that operating the above is as folthis pass sinks the tube to a size suitable for Z the reeling operation while simultaneously truing its shape. The tube is then rolled down the incline 6 to the inlet trough of the reeling maduce its outside diameter to that desirable for chine 2. As its size is positively regulated by the sinking-sizing machine 3, there is now no trouble in reeling it although little attention was paid to strict maintenance of any particular diameter when it was rolled.

It is apparent that the invention is not concerned with the old combination of a piercing mill, a longitudinal rolling mill and a set of cross rolls because of the fact that this does not present the same operating problems. Longitudinal rolling is done by stands of grooved rolls which may provide truly circular passes of set sizes whereas rotary rolling is done by means of rolls which causethe work to rotate about its axis while being worked in a more or less circumferential direction and which do not provide the circular pass of the former. Also, the latter roll the work to gage and size whereas a piercer simply opens up the billet for this operation.

This combination of a rolling mill, sinkingsizing machine and reeling machine enables a greatly increased output of tubes as it obviates close adjustment of the first mill.. Of course, so far as the rolling method itself is concerned, layouts other .than the one specifically shown and described might be used. The one shown is particularly advantageous because it conserves floor space, and the short travel of the tube reduces heat loss.

Weclaim:

1. A tube milllayout including a rotary rolling mill, a reeling machine and a sinking-sizing machine arranged between these two.

2. The methodof workinga tube consisting in rotary rolling it, then sizing it to a predetermined desirable outside diameter for reeling, and then reeling it. I

3. The method of making a tube consisting in rotary rolling a pierced billet to a tube having an outside diameter slightly larger than is desirable for reeling, giving this tube a pass through a sinking-sizing machine so as to rereeling, and then reeling said tube.

4. A tube mill layout including a rotary rolling mill, a sinking-sizing machine offset at the discharge side of said rolling mill, means for conveying the work to said sinking sizing machine, and a reeling machine beyond said sinking-sizing machine. 1

5. A tube mill layout including a rotary rolling mill, a sinking-sizing machine offset at the discharge side of said rolling mill, means for conveying the work to said sinking-sizing machine, and a reeling machine beyond said sinking-sizing machine. 1 1

6. The combination with a rotary rolling mill and a reeling machine, the latter being of a type that can only handle tubes whose outside diameters do not vary beyond a certain narrow range and the former being of a type that cannot uniformly produce tubes having outside diameters within said range, of a sinkigig-sizing machine providing a pass having a diameter within said range and positioned to operate on tubes leaving said mill and betore they reach said machine.

'1. The method of working tubes by a rotary rolling mill and a reeling machine when the latter can only handle tubes whose diameters do not vary beyond a certain narrow range and the former cannot uniformly produce tubes having diameters within this range, including deliberately rotary rolling pierced billets to tubes rolling mill and a reeling machine of the type having a fixedly positioned mandrel, including rolling pierced billets by said mill to tubes, longitudinally rolling said tubes to diameters determined by said machine and subsequently reeling said tubes in said machine.

- WILLIAM BARKI FRED w. wATERMAN. 

